The purpose of this core is to pursue and support the investigation of sex-specific factors in nicotine-dependence and treatment. The importance of this objective is supported by a growing empirical literature indicating sex-specific and sex-sensitive effects of nicotine and treatment response, and an attendant need to consider sex-related factors for the development of treatment strategies. The core supports all Center investigators, as well as collaborates with other institutional programs at Yale in order to enhance transdisciplinary investigation. Although the core initiates independent projects and conducts secondary data analyses to generate new models for understanding sex effects of nicotine and tobacco, its primary mission is cost-effective attention to sex-related factors in current and new projects through such means as pooling data to test sex-related hypotheses, including assessments related to sex and gender issues, ensuring adequate representation of women so that sex-related comparisons can be made, and guiding data analysis and interpretation of findings pertaining to sex differences for all appropriate Center projects. Improvement in the health of women and men depends upon new scientific knowledge that recognizes sex-related effects. The core is directed toward strengthening existing research in nicotine dependence as it relates to sex and gender, and developing new, cutting-edge areas of investigation that will result in direct practical benefit. The specific aims of the core are as follows: 1. Providing support and methodological consultation to investigators examining sex and gender effects in Center projects. 2. Investigating sex-specific and sex-sensitive factors in nicotine dependence and treatment. 3. Assessing sex-differences in perceived risks and benefits of smoking cessation. 4. Investigating the relationship of reproductive status and cyclicity to treatment response and relapse. 5. Generating new models to improve our understanding of multiple putative risk factors for smoking behavior from nationally-representative epidemiological data sets.